An area such as a building, residence, or office, may be protected with sensors distributed around a protected area. For example, a smoke sensor may be placed on the ceiling of several rooms in the building to detect fire in those rooms, or a water sensor may be placed under sinks to detect a leaking plumbing. When smoke or water is detected by a sensor, the sensor device may indicate an alarm condition, for example, with flashing lights or a loud sound emanating from the sensor device itself.
Some sensor systems communicate the sensor readings or alarm to a central location that may log the readings or sound a central alarm. A central alarm system, located at the premises of the areas protected by the sensor network, may allow an alarm to be enabled or disabled at a single central point for the entire premises. Where there are multiple sensors, a network of sensors may be connected to central alarm system. With a sensor network, a central alarm can cause alarm lights and sounds to emanate from all sensor devices when an alarm condition at only one sensor device is detected. In addition to sounding a local alarm, a central alarm system may notify an alert service, which may in turn notify local police or fire department. Generating an alert may, include generating a audio or visual indicator such as an alarm and may also include notifying an owner or resident of the area via a phone call or text message. Communication between sensors and the owner or local emergency services may be via a sensor hub and/or an service provider. Communication between sensor devices, a central hub, and an service may include physical wiring dedicated to the system, a wired or wireless computer network, or a telephone network.